Okay, so I'm a huge YouTube-aholic. It's my go-to place to discover new music, particularly from Korea and Japan. But, more to the point of this blog, there are also quite a few good RPG-related channels on YouTube. Below is a list of the one's I'm currently subscribed to (in alphabetical order, with notes on some):
GameGeeksRPG (just reviews of RPGs)
joesweeney88 (how-to vids on making RPG maps)
PaizoPublishing (Paizo Publishing's official channel)
tetsubo57 (mix of RPG vids and socio-political commentary)
ZombieNirvana (how-to vids on making RPG maps)
Note that most of these channels are part of the YouTube "RPG Brigade", a loose alliance of RPG-focused channels. The Gentleman Gamer did a great introductory vid to the brigade here: http://www.youtube.com/watch?v=ybXakkdA-l4.